Calculating Percent Change in Population

This video tutorial explains how to calculate the percent of increase and decrease using proportions. It begins with an introduction to the concept of percent change and the use of proportions. The tutorial provides a detailed example using population growth data to demonstrate the calculation of percent increase. It also addresses common misunderstandings students may have when setting up proportions, emphasizing the importance of using the original amount as the denominator. The lesson concludes with a review of the key concepts and calculations.

What is the main focus of this lesson?

• Learning about different types of graphs

• Understanding the history of Urbantown

• Exploring the concept of scale factors

• Calculating percent change using proportions

How is a proportion defined in this lesson?

• A method to calculate population growth

• A statement showing two ratios or rates are equal

• A way to measure height increase

• A comparison of two different numbers

In the example of Urbantown, what was the population in 2012?

• 14,000 people

• 12,000 people

• 2,500 people

• 10,000 people

What is the first step in calculating the percent increase in Urbantown's population?

• Identifying the original population

• Determining the scale factor

• Finding the new population

• Calculating the total population

How is the scale factor used in the calculation of percent increase?

• By multiplying the original amount

• By dividing the change by the original amount

• By subtracting the change from the original amount

• By adding the change to the original amount

What is the simplified fraction used in the calculation of Urbantown's population increase?

• 120 divided by 2,500

• 12 divided by 250

• 2,500 divided by 120

• 250 divided by 12

What is the rounded percent increase in Urbantown's population?

• 19%

• 21%

• 22%

• 20%

Why is it important to use the original amount in the denominator when calculating percent change?

• To avoid using decimals

• To make the numbers larger

• To compare the change to the starting amount

• To ensure the calculation is easier

What common mistake do students make when setting up the proportion for percent change?

• Using the wrong scale factor

• Forgetting to multiply by 100

• Adding instead of subtracting

• Using the new amount in the denominator

What would be implied if 14,500 was used as the denominator in the percent change calculation?

• The change was less than 2,500

• 14,500 was the initial population

• The population remained the same

• The population decreased